• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2003.10a
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• pp.391-396
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• 2003

The digital map expresses natural topography and artificial things with 3D position coordinates in the computer such as the road, railway, building, river, mountain, paddy and dryland. Therefore, those should contribute to the information-oriented society by maintaining information and providing it to users quickly. However it is difficult to maintain the most recent topographic information all the time because of restricted budget and time. The purpose of this study is to investigate and analyze the updating area of the digital map using remotely sensed data, and to furnish the useful information reducing cost and time. To predict updating area of the digital map, we applied the urban changes analysis method to Landsat TM images from produced date of the digital map to up-to-date. Classification method for urban change analysis applied single band process algorithm. This study presents that updating area of the digital map is predicted by only the rate of 40% on total research area.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2007.04a
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• pp.435-438
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• 2007

A laser scanning technique has been attracting much attention as a new technology to acquire location information. This technique might be applicable to a wide range of areas, most notably in geomatics, due to its high accuracy of location and automation of high-density data acquisition. In this study, the coastline was extracted using laser scanning. Through this laser scanning technique, efficient change detection of coast section can be ensured and also they can provide important information to be used when detecting a coast section in the future.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2007.04a
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• pp.289-293
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• 2007

Because the current numerical value map and update system in use do not reflect rapidly enough the transformation of topography, their usage are gradually in decrease. Therefore, there is an increasing demand for reception update system of numerical value map which can guarantee the accuracy and up-to-dateness of data. While rapid detection of topographical transformation is essential for rapid updating, the existing research based on remote investigation or direct measurement was difficult to apply efficiently in terms of cost and accuracy. Thereupon, this research aims to present efficient methods of detecting topographical transformations for a frequent real time updating of numerical value map using the topographical transformation and related data inputted in real time into the administrative information system.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.10b
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• pp.251-252
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• 2002

An algorithm has been developed to determine changes in surface topography on asperity level. The software stitches small but detailed images together to create one large image. If such an image is made before and after an experiment, their difference shows a direct 3D view of the changes in micro-geometry, rather than a change in surface parameters. The algorithm is described in detail and illustrated using artificial as well as real surfaces.

• Journal of Environmental Impact Assessment
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• v.23 no.2
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• pp.150-156
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• 2014

The aim of this study is to detection of changed vegetation area of Saemangeum tidal flat with comparison of topography and surface sediments during the dyke construction. Sedimentary facies of four seasons of 2001 from inside Saemangeum tidal flat revealed homogeneous layers in the upper part, however near sea side tidal flat were detecting with carried out rapid sediment deposition during the dyke construction using satellite image spatial analysis. The sedimentation types inside Saemangeum tidal flat were classified with vegetation types, which were well matched with the sedimentation pattern revealed by change in vegetation patterns.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.30 no.4
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• pp.49-58
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• 1998

The SPM could image the most detailed microstructure of a sample in a wet and dry state by measuring the interaction between the atoms on the sample surface and the extremely sharp probe tip. The refined fibre exhibited large wrinkles formed by fibrillar bundles, the disintegrated fibres extensively showed “scale-like features”. By using the Non-Contact Atomic Force Microscopy (NC-AFM) and Contact Atomic Force Microscopy (C-AFM) including Phase Detection Microscopy (PDM) and Force Modulation Microscopy (FMM), it was possible to investigate surface topography, surface roughness and mechanical property (hardness or visco-elasticity) of fibre surface in detail. The PDM and FMM images showed that the disintegrated only fibre displayed uniform mechanical properties, whereas the refined one did not. The surface roughness of pulp fibres was higher in refined fibres than in disintegrated fibres due to the presence of external fibrils. These SPM images would be used to provide visual evidence of morphological change of a single fibre created during mechanical treatments such as refining, drying, calendering and so on.

• Journal of Ocean Engineering and Technology
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• v.8 no.1
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• pp.84-95
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• 1994

In recent years Jin-Beach and Hyeya River mouth have experienced severe erosion phenomena. The cause of erosion is examined using a 3-dimensional nunumerical sediment transport model. The model is composed of three components : wave model, wave-induced current model and 3-dimensional sediment transport model. In the wave analysis component we consider refraction, diffraction and reflection based on Maruyama and Kajima method. For the wave-induced current model we use depth-integrated continuty equation and momentum equations. For the 3-dimensional sediment transport model we consider bed load and suspended load simutaneously. Model results obtained for Jin-ha Beach and Hyeya River mouth agreed well with experimental results.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2008.10a
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• pp.173-174
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• 2008

해안 침식이 진행되고 있는 부산 해운대 해수욕장을 중심으로 해수면 상승에 따른 해안선 변화에 대한 분석을 실시하였다. 1947년부터 2008년까지 항공사진을 활용하여 해안선을 추출하였는데 사진촬영시간에 따라 해안선의 위치가 현저히 변화하기 때문에 위치만으로는 비교할 수 없고, 평균적인 해안선 부근의 경사와 촬영시의 조수상태를 고려한 수심별 해빈 면적 산정 공식을 활용하여 해안선 면적을 구하였다. 또한 조위자료를 통하여 40년 동안의 해수면 상승량을 산출하고, 이를 바탕으로 미래의 해안선 후퇴거리를 계산해 보았다. 그 결과 3008년도 해빈 면적은 1947년도와 비교하면 약 29% 면적이 감소하였고, 1992년도에는 일시적으로 해빈 면적이 상승하는데 이는 양빈 사업으로 인한 것으로 이후 다시 감소현상을 보인다. 그리고 조위자료 분석 결과 해수면은 연평균 2.462mm/year의 속도로 상승하였다.

• Journal of Environmental Science International
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• v.20 no.6
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• pp.679-686
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• 2011

The characteristics of circulation in the coastal area of Jeju Harbor in Korea was examined using the Princeton Ocean Model(POM) with a sigma coordinate system. The result of numerical analysis well corresponded to the observed current data. The velocity at offshore was stronger compared to coastal area during the both period of in maximum flood and maximum ebb of spring tide. According to mean wind velocity, the tidal velocity at the shallow area of Jocheon was slightly increasing during maximum ebb. The effect of wind on the circulation was stronger in shallow area and showed rapid change with depth.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.1018-1022
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• 2000

Enhancement of the accuracy of products and productivity are essential to survive in a global industrial competition. This trend requires tighter dimensional tolerance specifications. To actively cope with the rapid change of the workpiece material and cutter geometry, a general method that can predict and analyze the machined surface is needed. Surface generation model for the prediction of the topography of machined surfaces is developed based on cutting force model considering cutter deflection and runout. This paper presents the method that constructs the three-dimensional machined surface error following the movement of a cutter, irrespective of the variations of cutting conditions. In addition, the effects of the cutting forces and the kink shape on the machined surface are extensively investigated.